PRE-SUBMISSION (Q-SUB) MEETING PACKAGE
EXECUTIVE SUMMARY
Prepared for: U.S. Food and Drug Administration Center for Devices and Radiological Health (CDRH) Office of Health Technology 2 (OHT2) Division of Chemistry and Toxicology Devices
Submitted by: Solstice Biomedical Inc. 220 Westbrook Drive, Suite 400 Cambridge, MA 02142
Right-click to update Table of Contents
1. Introduction and Purpose of the Pre-Submission
Solstice Biomedical Inc. ("SBI"), a Delaware corporation (File No. 7834291) and the U.S. subsidiary of Solstice Biomedical Devices Ltd. ("SBD"), an Irish private limited company (Companies Registration Office No. 648231), respectfully requests a Pre-Submission (Q-Sub) meeting with the Center for Devices and Radiological Health ("CDRH") of the U.S. Food and Drug Administration ("FDA") to discuss the regulatory strategy for the planned traditional 510(k) submission of the Solstice Lumina™ Continuous Glucose Monitoring (CGM) System.
The Solstice Lumina™ CGM System is an integrated continuous glucose monitoring platform comprising two device variants that are intended to function together as a single system and that will be submitted under one traditional 510(k):
• Lumina C14 — a subcutaneously implantable continuous glucose monitoring sensor; and
• Lumina R7 — a wearable reader/transmitter device.
Solstice intends to submit a traditional 510(k) submission to CDRH covering both the Lumina C14 sensor and the Lumina R7 reader/transmitter as a single system. This Pre-Submission Executive Summary and the accompanying Pre-Sub meeting package have been prepared in accordance with FDA's guidance document Requests for Feedback and Meetings for Medical Device Submissions: The Q-Submission Program (most recently revised January 2023) to facilitate a productive and efficient dialogue with the Agency prior to the formal 510(k) submission.
The purpose of this Pre-Submission meeting is to obtain FDA feedback on the following key topics:
1. Predicate device selection and substantial equivalence framework — including the appropriateness of the proposed primary and secondary predicate devices and whether identified technological differences raise new questions of safety or effectiveness;
2. Proposed performance and clinical testing plans — including the design, endpoints, and sample size of the planned pivotal clinical study, as well as the scope of bench performance testing;
3. Software documentation and cybersecurity approach — including the appropriateness of the software level of concern designation, documentation expectations, and cybersecurity considerations specific to the device's wireless architecture;
4. Biocompatibility testing scope — including whether the proposed ISO 10993-series testing program is sufficient for the C14 implantable sensor and R7 wearable reader; and
5. Potential iCGM classification pathway considerations — including whether the Lumina CGM System may be eligible for integrated CGM (iCGM) classification and the applicable special controls.
The full Pre-Submission meeting package accompanies this Executive Summary and includes the following separate sections, each of which provides detailed information on the respective topics:
• Device Description (detailed technical description of the Lumina C14 sensor and Lumina R7 reader/transmitter);
• Predicate Comparison and Substantial Equivalence Discussion;
• Proposed Performance Testing Plan;
• Proposed Clinical Study Protocol Summary (Protocol SBD-LUM-CL-001, "LUMINA-US"); and
• Questions for FDA.
This Executive Summary is intended to provide CDRH reviewers with a concise overview of the subject device, the sponsor, the proposed regulatory pathway, and the key topics for which Solstice seeks FDA feedback, so as to facilitate an efficient and focused Pre-Submission meeting.
2. Sponsor Information
The intended 510(k) applicant and device registration holder for the Solstice Lumina™ CGM System is Solstice Biomedical Inc., the U.S. operating subsidiary of Solstice Biomedical Devices Ltd. Key corporate and personnel information is provided below.
Intended 510(k) Applicant / Registration Holder:
Solstice Biomedical Inc. (SBI) 220 Westbrook Drive, Suite 400 Cambridge, MA 02142 United States
Delaware corporation, File No. 7834291
Parent Company:
Solstice Biomedical Devices Ltd. (SBD) Unit 14, Liffey Innovation Park Chapelizod, Dublin D20 FX72 Ireland
Irish private limited company, Companies Registration Office No. 648231
Industry Focus: Solstice Biomedical Devices Ltd. and its subsidiaries are focused on the development, manufacture, and commercialization of medical devices and biotechnology products, with a core competency in electrochemical biosensors and wearable diagnostic technologies. The company's research and development activities are centered on advancing point-of-care and continuous monitoring platforms for chronic metabolic conditions, with a particular emphasis on diabetes mellitus.
Company Size: Solstice employs approximately 820 individuals globally across its Dublin headquarters, manufacturing facility in Galway, Ireland, and offices in Cambridge, Massachusetts. The U.S. subsidiary, Solstice Biomedical Inc., currently employs approximately 95 individuals, including regulatory, clinical, quality, and commercial personnel responsible for the company's U.S. operations and market access activities.
Key Personnel:
Solstice's regulatory affairs, quality assurance, and clinical development functions are managed from the company's Dublin headquarters, with regulatory strategy for the U.S. market coordinated in partnership with the U.S. subsidiary. Dr. Niamh Tierney serves as the primary regulatory contact for all communications with FDA regarding this Pre-Submission and the planned 510(k), while Marcus Hale is available as the U.S.-based point of contact for scheduling, correspondence, and operational matters.
3. Regulatory History of the Sponsor
3.1 Prior FDA Clearance
Solstice has prior experience with the FDA premarket review process. Solstice Biomedical Inc. previously obtained 510(k) clearance for the GlucoStrip RX-200 Test Strip Reader, a Class II in vitro diagnostic glucose test strip reader device, under 510(k) No. K192847. This clearance was issued by FDA on November 14, 2019, under product code NBW (System, Test, Blood Glucose, Over the Counter).
The GlucoStrip RX-200 Test Strip Reader is referenced herein solely for purposes of demonstrating Solstice's corporate pedigree and its prior history of interaction with CDRH. It is important to note that the GlucoStrip RX-200 is not proposed as a predicate device for the substantial equivalence determination for the Lumina CGM System. The Lumina CGM System represents a significant technology evolution from the earlier-generation glucose test strip reader platform, transitioning from a discrete, fingerstick-based blood glucose testing modality to a continuous, subcutaneously implanted, real-time glucose monitoring system. While both products share the common therapeutic domain of glucose measurement in persons with diabetes, the technological platform, measurement methodology, form factor, and clinical application of the Lumina CGM System are fundamentally distinct from those of the GlucoStrip RX-200.
Notwithstanding the foregoing, Solstice's experience with the 510(k) process for the GlucoStrip RX-200 has informed the company's understanding of FDA's expectations regarding premarket submissions, quality system requirements, and labeling practices, and Solstice has applied this institutional knowledge in the development and regulatory planning for the Lumina CGM System.
3.2 EU MDR Certification and Commercial History
The Solstice Lumina™ CGM System holds a valid European Union Medical Device Regulation (EU MDR 2017/745) CE certificate. The certificate details are as follows:
Certificate Number: MCA-2024-07319 Date of Issuance: September 12, 2024 Issuing Notified Body: Meridian Conformity Assessment GmbH (Notified Body No. NB 0483), Landsberger Allee 44, 10249 Berlin, Germany
Commercial launch of the Solstice Lumina™ CGM System in the European Union commenced in September 2024, concurrent with the issuance of the CE certificate. As of the date of this Pre-Submission package, the Lumina CGM System is commercially available in Germany, France, the Netherlands, Ireland, and the United Kingdom (under UKCA marking), and Solstice is actively pursuing additional EU member state market access.
Additionally, Solstice Biomedical Devices Ltd. holds a current ISO 13485:2016 quality management system certification, issued by Meridian Conformity Assessment GmbH (NB 0483), covering the design, development, manufacture, and distribution of in vitro diagnostic and continuous glucose monitoring medical devices. This certification applies to the company's headquarters in Dublin and its manufacturing facility in Galway, Ireland.
It should be noted that the Solstice Lumina™ CGM System has no existing FDA clearance or approval in the United States. This Pre-Submission and the subsequent traditional 510(k) submission represent the initial regulatory pathway for U.S. market entry. Solstice is committed to providing FDA with a complete, transparent, and high-quality submission that reflects both the company's EU MDR regulatory experience and FDA's specific premarket review expectations.
4. Device Overview
4.1 Product Line
Product Line Name: Solstice Lumina™ CGM System
The Solstice Lumina™ CGM System is an integrated continuous glucose monitoring platform that comprises two device variants designed and intended to function together as a unified system for real-time glucose monitoring in persons with diabetes mellitus. The two device variants — the Lumina C14 implantable sensor and the Lumina R7 wearable reader/transmitter — are interdependent components of a single system architecture. The C14 sensor acquires interstitial glucose measurements and wirelessly transmits data to the R7 reader/transmitter, which processes and displays glucose information to the user and relays data to the companion mobile application. Neither the C14 sensor nor the R7 reader/transmitter is intended to be marketed, distributed, or used as a standalone device independent of the other system component.
A detailed technical description of each device variant, including materials, dimensions, functional specifications, and design drawings, is provided in the separate Device Description section of the Pre-Sub meeting package. The following subsections provide a summary overview for purposes of this Executive Summary.
4.2 Lumina C14 — Implantable Sensor
The Lumina C14 is a subcutaneously implantable continuous glucose monitoring sensor designed for insertion into the subcutaneous tissue of the posterior upper arm using a proprietary single-use applicator (the Lumina Applicator, included as an accessory to the system).
The C14 sensor employs a fourth-generation enzymatic electrochemical biosensor based on Solstice's proprietary platinum-iridium electrode coating technology, designated internally as "PtIr-4G." The PtIr-4G electrode features a multi-layered enzyme membrane system with glucose oxidase immobilized on a nanoporous platinum-iridium alloy substrate, which provides enhanced signal stability, reduced oxygen dependence, and improved resistance to interferent substances compared to conventional platinum-based electrode designs. The sensor operates by measuring the electrochemical current generated by the enzymatic oxidation of glucose in the interstitial fluid, which is then correlated to blood glucose concentration through the proprietary LuminaPredict algorithm.
Key technical specifications of the Lumina C14 sensor include:
• Sensor wear duration: 14 days (336 hours)
• Wireless data transmission protocol: Bluetooth Low Energy (BLE) 5.2
• Glucose measurement range: 40–400 mg/dL
• Warm-up time: ≤ 60 minutes from sensor insertion to first glucose reading
• Sampling frequency: Every 1 minute; glucose value reported to user every 5 minutes
• Current firmware version: Lumina Firmware v3.4.2
• Sterilization method: Ethylene oxide (EO)
• Shelf life: 18 months from date of manufacture (when stored per labeled conditions)
The C14 sensor is a single-use, disposable device intended for replacement at the end of the 14-day wear period. The sensor is supplied in a sterile, individually packaged configuration with the Lumina Applicator pre-loaded for user self-insertion.
4.3 Lumina R7 — Wearable Reader/Transmitter
The Lumina R7 is a wearable reader/transmitter device designed to be worn on the upper arm in proximity to the implanted C14 sensor. The R7 reader/transmitter serves as the primary user interface for the Solstice Lumina™ CGM System, receiving glucose measurement data wirelessly from the C14 sensor, processing and displaying glucose information, and providing user-configurable alerts and notifications.
Key features and technical specifications of the Lumina R7 reader/transmitter include:
• Form factor: Compact, arm-worn device with integrated display and adhesive patch for secure attachment to the skin of the upper arm
• Data reception: Receives BLE 5.2 data from the Lumina C14 sensor
• Display capabilities: Real-time glucose values (numerical), directional trend arrows (indicating rate and direction of glucose change), and 8-hour trend graphs (graphical display of glucose history)
• Alert functionality: Configurable hypoglycemia and hyperglycemia alerts, with user-adjustable threshold settings; alert latency of ≤ 5 minutes from sensor reading to user notification (including audible, vibration, and visual alert modalities)
• Connectivity: Communicates with the Solstice Lumina™ mobile application (available on iOS and Android platforms) via Bluetooth Low Energy for data synchronization, remote monitoring, and cloud-based data sharing with healthcare providers
• Battery life: Rechargeable lithium-polymer battery; minimum 7-day battery life per full charge under typical use conditions
• Current software version: Lumina Reader OS v2.1.0
• Associated software components:
• LuminaPredict Algorithm v2.1 — Solstice's proprietary glucose prediction algorithm, which processes raw electrochemical data from the C14 sensor and generates calibrated glucose values, trend information, and predictive glucose alerts
• Lumina Mobile App v1.0.3 — companion mobile application for iOS and Android, enabling extended data visualization, report generation, and data sharing
The R7 reader/transmitter is a reusable, non-disposable device intended for use across multiple sensor wear cycles. The device is not implanted and is classified as a skin-contacting, externally worn device for biocompatibility evaluation purposes.
5. Intended Use and Indications for Use
The proposed intended use and indications for use statement for the Solstice Lumina™ CGM System, as anticipated to be included in the planned 510(k) submission, is as follows:
Intended Use: The Solstice Lumina™ Continuous Glucose Monitoring (CGM) System is intended for the continuous monitoring of glucose levels in the interstitial fluid of persons aged 18 and older with Type 1 or Type 2 diabetes mellitus. The system is intended for prescription use.
Indications for Use: The Solstice Lumina™ CGM System is indicated for use by persons aged 18 years and older with Type 1 or Type 2 diabetes mellitus for the continuous monitoring of glucose levels. The system provides real-time glucose readings, glucose trend information (including directional trend arrows and trend graphs), and configurable hypoglycemia and hyperglycemia alerts to aid in the management of diabetes. The system measures glucose in the range of 40 to 400 mg/dL over a continuous sensor wear duration of up to 14 days (336 hours). The Solstice Lumina™ CGM System is intended for prescription use only.
Solstice notes that the proposed intended use and indications for use are consistent with those of the identified primary and secondary predicate devices and with the current scope of the product code QKQ classification. Solstice seeks FDA feedback during the Pre-Submission meeting on the appropriateness and completeness of this intended use statement, including whether any modifications would be necessary to align with FDA's current expectations for continuous glucose monitoring devices or the iCGM classification pathway.
The Solstice Lumina™ CGM System is not intended for use in the following populations or applications:
• Persons under the age of 18;
• Pregnant women (a separate clinical study would be required to support this population);
• As a replacement for self-monitoring blood glucose (SMBG) testing for therapeutic decision-making, unless and until iCGM classification is obtained and applicable special controls are met;
• For use in critical care or hospital inpatient settings.
These contraindications and limitations will be clearly stated in the device labeling as part of the 510(k) submission.
6. Proposed Regulatory Pathway
6.1 Submission Type and Classification
Solstice Biomedical Inc. proposes to submit a traditional 510(k) premarket notification for the Solstice Lumina™ CGM System, covering both the Lumina C14 implantable sensor and the Lumina R7 wearable reader/transmitter as a single integrated system under one submission. Solstice has determined that a traditional 510(k) is the appropriate submission type based on the availability of suitable predicate devices, the Class II classification of those predicates, and the nature and scope of the technological differences between the subject device and the proposed predicates.
The anticipated regulatory classification parameters for the Lumina CGM System are as follows:
Product Code: QKQ (Electrode, Glucose, Subcutaneous)
Device Class: Class II (with special controls)
Regulation Number: 21 C.F.R. § 862.1355 (Glucose test system), as updated per FDA's reclassification order effective March 2024, which established the iCGM device type and associated special controls within this regulation number
Solstice acknowledges that the product code QKQ encompasses both traditional CGM devices and integrated CGM (iCGM) devices, and that the applicable special controls differ depending on whether the device is classified as a standard CGM or as an iCGM. Solstice seeks FDA feedback during the Pre-Submission meeting on the appropriateness of the QKQ product code classification and, specifically, whether the Lumina CGM System may qualify for the iCGM classification pathway based on the device's performance characteristics and the proposed clinical study design.
If FDA determines that the Lumina CGM System may be eligible for iCGM classification, Solstice would welcome the opportunity to discuss the specific special controls applicable to iCGM devices and any additional testing, data, or labeling requirements that would be necessary to support the iCGM designation within the planned 510(k) submission.
6.2 Predicate Device Selection (Summary)
Solstice has identified two predicate devices and one additional reference device for purposes of the substantial equivalence determination. The predicate selection rationale is summarized below, with a detailed predicate comparison and substantial equivalence discussion provided in the separate section of the Pre-Sub meeting package.
Primary Predicate Device:
Device Name: NovaSense Medical Technologies Inc. GlucoTrack NX-500 CGM System 510(k) Number: K211034 Date of FDA Clearance: June 18, 2022 Product Code: QKQ Device Class: Class II
The NovaSense GlucoTrack NX-500 is a continuous glucose monitoring system comprising a subcutaneously implantable enzymatic electrochemical sensor and a handheld receiver. The NX-500 features a 10-day sensor wear duration and transmits glucose data from the implanted sensor to the handheld receiver via Bluetooth Low Energy. The NX-500 was selected as the primary predicate based on its substantial similarity to the Lumina CGM System in terms of intended use, technological characteristics, measurement methodology, and clinical application. Both the NX-500 and the Lumina CGM System employ enzymatic electrochemical sensing for continuous interstitial glucose measurement and are intended for the management of diabetes mellitus in adults.
Secondary Predicate (Reference Device):
Device Name: NovaSense Medical Technologies Inc. GlucoTrack NX-700 CGM System 510(k) Number: K230489 Date of FDA Clearance: March 7, 2024 Product Code: QKQ Device Class: Class II
The NovaSense GlucoTrack NX-700 is the successor to the NX-500 and features an extended 14-day sensor wear duration, enhanced BLE 5.0 transmission, and an updated proprietary glucose algorithm. The NX-700 is identified as a secondary predicate (reference device) to support the substantial equivalence discussion with respect to specific technological features of the Lumina CGM System that differ from the NX-500 primary predicate, most notably the 14-day sensor wear duration. The NX-700 demonstrates that a 14-day wear duration has been previously cleared by FDA for an enzymatic electrochemical CGM system within the same product code and classification.
Additional Reference (Corporate Pedigree Only):
Device Name: Solstice Biomedical Inc. GlucoStrip RX-200 Test Strip Reader 510(k) Number: K192847 Date of FDA Clearance: November 14, 2019 Product Code: NBW Device Class: Class II
The GlucoStrip RX-200 is referenced solely for purposes of establishing Solstice's corporate pedigree and prior FDA interaction history. The GlucoStrip RX-200 is not proposed as a predicate device for the substantial equivalence determination for the Lumina CGM System. The GlucoStrip RX-200 operates under a different product code, employs a fundamentally different measurement methodology (discrete test strip-based blood glucose testing versus continuous electrochemical interstitial glucose monitoring), and is not technologically comparable to the Lumina CGM System for purposes of substantial equivalence analysis.
A comprehensive predicate comparison table, including a feature-by-feature analysis of the subject device and both predicate devices across all relevant technological and performance parameters, is provided in the Predicate Comparison and Substantial Equivalence Discussion section of the Pre-Sub meeting package.
6.3 Key Differences from Primary Predicate (K211034)
Solstice has identified the following five principal differences between the Solstice Lumina™ CGM System and the primary predicate device, the NovaSense GlucoTrack NX-500 (K211034). A detailed analysis of each difference, including its impact on safety and effectiveness and the testing proposed to address each difference, is provided in the Predicate Comparison and Substantial Equivalence Discussion section of the Pre-Sub meeting package. The differences are summarized as follows:
1. Sensor Wear Duration: The Lumina C14 sensor has a 14-day (336-hour) wear duration compared to the 10-day (240-hour) wear duration of the NX-500. This extended wear duration is consistent with the secondary predicate NX-700 (K230489), which also features a 14-day sensor wear duration and has been cleared by FDA under the same product code and classification. Solstice will provide performance and clinical data demonstrating sensor accuracy and reliability through the full 14-day wear period.
2. Electrode Material: The Lumina C14 sensor employs a proprietary platinum-iridium alloy electrode coating (PtIr-4G technology), whereas the NX-500 utilizes a conventional platinum electrode. The PtIr-4G electrode is designed to provide enhanced signal stability and reduced interferent sensitivity. Solstice will provide bench testing data (including interference testing per FDA's glucose monitoring guidance) and biocompatibility data (including evaluation of the PtIr-4G coating material per ISO 10993) to demonstrate that this material change does not adversely affect device safety or effectiveness.
3. Bluetooth Low Energy Version: The Lumina CGM System utilizes BLE 5.2 for wireless communication between the C14 sensor and R7 reader/transmitter, whereas the NX-500 uses BLE 5.0. BLE 5.2 provides improved data throughput, enhanced connection stability, and additional security features compared to BLE 5.0. Solstice will provide wireless coexistence testing data and cybersecurity documentation to demonstrate that the use of BLE 5.2 does not introduce new safety or security risks.
4. Reader Form Factor: The Lumina R7 is an arm-worn integrated reader/transmitter, whereas the NX-500 employs a handheld receiver. The arm-worn form factor of the R7 is designed to enable continuous, passive data reception without requiring the user to actively scan or position a handheld receiver. Solstice will provide human factors data and biocompatibility data for the skin-contacting adhesive to address this difference.
5. Glucose Algorithm: The Lumina CGM System employs Solstice's proprietary glucose prediction algorithm (LuminaPredict v2.1), whereas the NX-500 uses NovaSense's proprietary algorithm. The LuminaPredict algorithm processes raw electrochemical data from the C14 sensor and generates calibrated glucose values, trend information, and predictive alerts. Solstice will provide software verification and validation documentation, algorithm performance data, and clinical accuracy data to demonstrate that the LuminaPredict algorithm provides glucose measurement accuracy consistent with or superior to the predicate device.
It is Solstice's position that these differences, individually and collectively, do not raise new questions of safety or effectiveness that would preclude a finding of substantial equivalence. Each identified difference is addressed by an evolutionary technological improvement within the same fundamental technology platform (enzymatic electrochemical CGM), and in several cases the specific feature in question (e.g., 14-day wear duration, BLE 5.x transmission) has already been cleared by FDA in the secondary predicate or other legally marketed CGM devices within the same product code. Detailed justification for this position, supported by a comprehensive predicate comparison and proposed testing strategy, is provided in the accompanying Substantial Equivalence Discussion section of the Pre-Sub meeting package.
7. Overview of Proposed Testing and Clinical Strategy
7.1 Performance Testing
Solstice has developed a comprehensive performance testing plan designed to demonstrate the safety and effectiveness of the Solstice Lumina™ CGM System and to address each of the identified technological differences from the primary predicate device. The proposed performance testing program encompasses bench testing, biocompatibility testing, electromagnetic compatibility and electrical safety testing, and software verification and validation, including a cybersecurity assessment. A detailed Proposed Performance Testing Plan, including specific test protocols, acceptance criteria, and applicable standards, is provided in the separate section of the Pre-Sub meeting package.
Bench Testing (Summary):
The proposed bench testing program includes, but is not limited to, the following categories of testing:
• Sensor accuracy testing: Evaluation of the Lumina C14 sensor's measurement accuracy across the full glucose range (40–400 mg/dL) under controlled laboratory conditions, including assessment of accuracy at low, normal, and high glucose concentrations;
• Linearity testing: Demonstration of the linear relationship between glucose concentration and sensor signal output across the measurement range;
• Precision testing: Assessment of within-sensor and between-sensor reproducibility, including repeatability and intermediate precision evaluations;
• Interference testing: Evaluation of the C14 sensor's susceptibility to common endogenous and exogenous interferent substances (e.g., acetaminophen, ascorbic acid, uric acid, maltose, galactose) in accordance with FDA's guidance on blood glucose monitoring test systems and relevant consensus standards;
• Sensor stability and drift testing: Evaluation of sensor signal stability and drift over the full 14-day wear duration under simulated physiological conditions;
• Wireless performance testing: Assessment of BLE 5.2 communication range, reliability, and data integrity between the C14 sensor and R7 reader/transmitter under typical use conditions and in the presence of common wireless interference sources.
Biocompatibility Testing:
Biocompatibility testing will be conducted in accordance with the ISO 10993 series of standards, with the scope of testing tailored to the nature and duration of tissue contact for each device component.
For the Lumina C14 implantable sensor (implant device with prolonged subcutaneous tissue contact of up to 14 days), the proposed biocompatibility testing scope includes:
• Cytotoxicity (ISO 10993-5)
• Sensitization (ISO 10993-10)
• Irritation (ISO 10993-10)
• Acute systemic toxicity (ISO 10993-11)
• Subchronic toxicity (ISO 10993-11)
• Implantation (ISO 10993-6)
• Hemocompatibility (ISO 10993-4)
• Genotoxicity (ISO 10993-3)
The biocompatibility testing program for the C14 sensor will include specific evaluation of the PtIr-4G electrode coating material, including extractables and leachables characterization, to address the novel electrode material composition as a technological difference from the primary predicate.
For the Lumina R7 wearable reader/transmitter (external device with prolonged skin contact via adhesive patch), the proposed biocompatibility testing scope includes:
• Cytotoxicity (ISO 10993-5)
• Sensitization (ISO 10993-10)
• Irritation (ISO 10993-10)
EMC and Electrical Safety Testing:
Electromagnetic compatibility (EMC) and electrical safety testing will be conducted in accordance with applicable FDA-recognized consensus standards, including IEC 60601-1 (Medical Electrical Equipment — General Requirements for Basic Safety and Essential Performance) and IEC 60601-1-2 (EMC requirements and tests). Wireless coexistence testing will be conducted in accordance with ANSI C63.27.
Software Verification and Validation:
Software verification and validation activities will encompass all software components of the Lumina CGM System, including the Lumina Firmware (C14), Lumina Reader OS (R7), LuminaPredict Algorithm, and Lumina Mobile App. Testing will be conducted in accordance with FDA's guidance on Content of Premarket Submissions for Device Software Functions and IEC 62304:2006/A1:2015 (Medical device software — Software life cycle processes). A cybersecurity assessment will be conducted in accordance with FDA's guidance Cybersecurity in Medical Devices: Quality System Considerations and Content of Premarket Submissions (September 2023), including threat modeling, vulnerability assessment, and documentation of cybersecurity controls. Additional detail on the software and cybersecurity approach is provided in Section 8 below and in the separate sections of the Pre-Sub meeting package.
Testing Laboratory:
All bench performance testing, biocompatibility testing, and EMC/electrical safety testing will be conducted by Whitmore Laboratories Inc., a nationally recognized testing laboratory accredited by the American Association for Laboratory Accreditation (A2LA) under Certificate No. 3847.01.
Whitmore Laboratories Inc. 1625 Shady Grove Road, Suite 300 Gaithersburg, MD 20878
Biocompatibility Testing Target Completion: August 31, 2025
The detailed Proposed Performance Testing Plan, including specific test protocols, sample sizes, acceptance criteria, test conditions, and applicable consensus standards, is provided in the separate section of the Pre-Sub meeting package.
7.2 Clinical Study
Solstice has developed a proposed pivotal clinical study protocol to generate the clinical performance data necessary to support the planned 510(k) submission. The study protocol has been designated Protocol SBD-LUM-CL-001 and is titled "LUMINA-US: A Prospective, Single-Arm, Multicenter Study to Evaluate the Accuracy and Safety of the Solstice Lumina™ Continuous Glucose Monitoring System in Adults with Type 1 and Type 2 Diabetes Mellitus."
A detailed Proposed Clinical Study Protocol Summary is provided in the separate section of the Pre-Sub meeting package. The key elements of the proposed study design are summarized below.
Study Design: Prospective, single-arm, multicenter clinical study.
Study Population: The study will enroll 350 subjects — 175 subjects with Type 1 diabetes mellitus and 175 subjects with Type 2 diabetes mellitus — at six (6) U.S. clinical sites. The balanced enrollment across diabetes types is intended to demonstrate device performance across the spectrum of glycemic variability encountered in the intended use population.
Primary Endpoint: Sensor accuracy, measured by Mean Absolute Relative Difference (MARD), with a pre-specified performance target of MARD ≤ 9.0%. This MARD target is consistent with FDA's current expectations for iCGM classification as articulated in FDA's guidance document Integrated Continuous Glucose Monitoring Systems (September 2023) and is intended to support both the traditional 510(k) substantial equivalence determination and, if applicable, the iCGM classification pathway.
Additional Endpoints:
• Safety evaluation: Assessment of device-related adverse events, including sensor insertion site reactions (e.g., erythema, edema, infection), device malfunctions, and any serious adverse events;
• User labeling comprehension: Assessment of user understanding of device labeling, including instructions for use, alert interpretation, and sensor insertion procedures, through a structured labeling comprehension study component;
• Consensus Error Grid analysis: ≥ 99% of paired data points (CGM glucose versus reference venous blood glucose) falling within Zones A and B of the Clarke Error Grid Analysis, consistent with the analytical accuracy expectations for CGM devices in the current literature and FDA guidance.
Reference Method: Venous blood glucose measured by a laboratory reference method (YSI 2900 Biochemistry Analyzer or equivalent FDA-cleared laboratory glucose analyzer) at defined time points during in-clinic sessions.
Estimated Study Duration: Approximately 6 months total, comprising approximately 14 weeks of subject enrollment, a 14-day sensor wear period per subject (with a minimum of three in-clinic sessions per subject for reference glucose comparisons), and approximately 8 weeks of data analysis, statistical analysis, and clinical study report preparation.
Planned Study Start: September 15, 2025 (subject to Pre-Sub meeting feedback from FDA and Institutional Review Board approval).
Contract Research Organization (CRO):
Veltrano Clinical Research Organization Inc. 500 North Capitol Street, Suite 700 Indianapolis, IN 46204
Dr. Lisa Fontaine, VP of Clinical Operations
Institutional Review Board (IRB):
Clearwater Institutional Review Board LLC IRB Registration No. IRB-2019-04821 3200 Bayshore Boulevard Tampa, FL 33629
IDE Exemption Applicability:
Solstice anticipates that the LUMINA-US clinical study will qualify for the Investigational Device Exemption (IDE) exemption under 21 C.F.R. § 812.2(c)(3) as a non-significant risk (NSR) diagnostic device study. Specifically, Solstice submits that the Lumina CGM System is a diagnostic device that, when used in accordance with the proposed study protocol, does not pose a significant risk to subjects because: (a) the device is not intended to be used as the sole basis for therapeutic decision-making during the study period; (b) subjects will continue their standard diabetes management regimen throughout the study; (c) the C14 sensor is a minimally invasive, subcutaneously implanted device with a limited 14-day wear duration and a well-characterized risk profile consistent with legally marketed CGM devices; and (d) the study does not involve vulnerable populations or life-sustaining applications.
Solstice seeks confirmation from FDA during the Pre-Submission meeting that the proposed LUMINA-US study qualifies for the IDE exemption under 21 C.F.R. § 812.2(c)(3) and does not require a separate IDE application.
8. Software and Cybersecurity Overview
The Solstice Lumina™ CGM System incorporates multiple software components that are integral to the device's function. Solstice has developed these software components in accordance with IEC 62304:2006/A1:2015 and has classified the software and cybersecurity risk in accordance with applicable FDA guidance. A detailed software description and cybersecurity documentation plan is provided in the separate sections of the Pre-Sub meeting package.
Software Level of Concern: Solstice has designated the overall Software Level of Concern for the Lumina CGM System as Major, in accordance with FDA's guidance on Content of Premarket Submissions for Device Software Functions and the software safety classification framework of IEC 62304:2006/A1:2015. This designation reflects the determination that the software could directly or indirectly result in serious injury to the patient if it fails or produces erroneous glucose readings — for example, if an inaccurate glucose value or a missed hypoglycemia alert were to lead to inappropriate insulin dosing or failure to treat a hypoglycemic episode. Solstice believes that the Major designation is appropriate and seeks FDA feedback on this classification during the Pre-Submission meeting.
Software Components: The following software components are included within the scope of the Lumina CGM System and will be documented in the 510(k) submission:
Cybersecurity Approach:
Solstice's cybersecurity approach for the Lumina CGM System is aligned with FDA's guidance document Cybersecurity in Medical Devices: Quality System Considerations and Content of Premarket Submissions (September 2023). Key elements of the cybersecurity approach include:
• Threat Modeling: Solstice has completed a comprehensive threat model for the Lumina CGM System using the STRIDE framework (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege). The threat model identifies potential cybersecurity threats to the BLE 5.2 wireless communication link between the C14 sensor and R7 reader/transmitter, the BLE communication link between the R7 reader/transmitter and the Lumina Mobile App, and the data storage and transmission pathways within the mobile app (including cloud-based data synchronization). Mitigation strategies for each identified threat have been documented and are implemented in the device design.
• Software Bill of Materials (SBOM): A complete Software Bill of Materials (SBOM) will be included in the 510(k) submission, covering all software components, third-party libraries, open-source components, and firmware dependencies. The SBOM will be provided in a machine-readable format consistent with FDA expectations and industry standards (e.g., SPDX or CycloneDX format).
• Security Controls: The Lumina CGM System incorporates the following security controls, among others: BLE 5.2 Secure Connections with AES-128-CCM encryption; mutual authentication between the C14 sensor and R7 reader/transmitter; encrypted data storage on the R7 reader/transmitter and mobile app; secure boot and firmware integrity verification on both the C14 and R7 devices; and over-the-air (OTA) firmware update capability with cryptographic signature verification.
• Vulnerability Disclosure and Patch Management: Solstice has established a coordinated vulnerability disclosure policy and a post-market software update and patch management process to address identified vulnerabilities throughout the device lifecycle.
Solstice seeks FDA feedback during the Pre-Submission meeting on the following cybersecurity-related topics: (a) the specific software documentation requirements and level of detail expected for the BLE 5.2 wireless communication architecture; (b) the scope of the SBOM; (c) the adequacy of the threat model; and (d) any additional cybersecurity testing or documentation that FDA would recommend for inclusion in the 510(k) submission. Detailed questions on these topics are included in the Questions for FDA section of the Pre-Sub meeting package.
9. Proposed Regulatory Timeline
Solstice has developed the following proposed regulatory timeline for the Lumina CGM System U.S. market entry program. This timeline has been developed with the objective of providing a complete and high-quality 510(k) submission that fully reflects FDA feedback from the Pre-Submission meeting, while maintaining a target for U.S. commercial launch in the fourth quarter of 2026.
Solstice notes that the timeline outlined above is contingent upon several factors, including the scheduling and outcome of the Pre-Submission meeting, the results and timing of bench performance and biocompatibility testing, IRB approval and clinical site activation for the LUMINA-US study, clinical study enrollment and data quality, and the duration of FDA's review of the 510(k) submission. Solstice is committed to maintaining open communication with FDA throughout the regulatory process and will promptly notify the Agency of any material changes to the anticipated timeline.
The submission timeline has been developed with the objective of ensuring that Solstice has sufficient time to incorporate FDA feedback from the Pre-Submission meeting into the study design, testing plans, and submission strategy, thereby minimizing the likelihood of additional information requests or review delays during the 510(k) review process.
10. Summary of Questions for FDA
Solstice Biomedical Inc. is seeking FDA guidance on the following topics in connection with the planned traditional 510(k) submission for the Solstice Lumina™ CGM System. The questions summarized below are presented in full, with supporting context and background information, in the separate Questions for FDA section of the Pre-Sub meeting package. Solstice respectfully requests that FDA provide written feedback on these questions in advance of the Pre-Submission meeting, to the extent feasible, so as to facilitate a productive and efficient discussion during the meeting.
Topic 1 — Predicate Acceptance and Substantial Equivalence Framework:
Solstice seeks FDA feedback on the appropriateness of the NovaSense GlucoTrack NX-500 CGM System (K211034) as the primary predicate device and the NovaSense GlucoTrack NX-700 CGM System (K230489) as the secondary predicate (reference device) for the substantial equivalence determination. Specifically, Solstice seeks FDA's assessment of whether the five identified technological differences between the Lumina CGM System and the primary predicate (sensor wear duration, electrode material, BLE version, reader form factor, and glucose algorithm) raise new questions of safety or effectiveness that cannot be adequately addressed through the proposed performance and clinical testing program.
Topic 2 — Clinical Study Design and Endpoints:
Solstice seeks FDA feedback on the acceptability of the proposed LUMINA-US pivotal clinical study design, including: (a) the single-arm, multicenter study design; (b) the proposed sample size of 350 subjects (175 Type 1 diabetes + 175 Type 2 diabetes); (c) the primary endpoint of MARD ≤ 9.0%; (d) the Clarke Error Grid criterion of ≥ 99% of paired data points in Zones A+B; and (e) the proposed reference method (YSI 2900 or equivalent). Solstice also seeks guidance on whether additional endpoints or study design elements would be recommended by FDA to support the 510(k) submission or, if applicable, the iCGM classification pathway.
Topic 3 — IDE Exemption Applicability:
Solstice seeks FDA confirmation that the LUMINA-US clinical study qualifies for the IDE exemption under 21 C.F.R. § 812.2(c)(3) as a non-significant risk (NSR) diagnostic device study, and that a separate IDE application is not required prior to commencing the study.
Topic 4 — Software Documentation Requirements: